private static ushort GetMaskedVersion(ushort version, VersionMaskType versionMaskType)
{
if (versionMaskType == VersionMaskType.None)
{
return version;
}
else
{
return (ushort)(0xFFFF - version);
}
}
private static ushort GetMaskedVersion(ushort version, VersionMaskType versionMaskType)
{
if (versionMaskType == VersionMaskType.None)
{
return(version);
}
else
{
return((ushort)(0xFFFF - version));
}
}
/// <summary>
/// Creates a new <see cref="RollingIv"/> instance.
/// </summary>
/// <param name="initialIv">The initial IV for the new instance.</param>
/// <param name="versionMaskType">The <see cref="VersionMaskType"/> for the new instance.</param>
/// <returns>a new instance of <see cref="RollingIv"/>.</returns>
public RollingIv CreateEncryptIv(byte[] initialIv, VersionMaskType versionMaskType)
{
ushort versionMask = GetMaskedVersion(this.version, versionMaskType);
return new RollingIv(this.encryptionAlgorithm, initialIv, versionMask);
}
/// <summary>
/// Creates a new <see cref="RollingIv"/> instance.
/// </summary>
/// <param name="initialIv">The initial IV for the new instance.</param>
/// <param name="versionMaskType">The <see cref="VersionMaskType"/> for the new instance.</param>
/// <returns>a new instance of <see cref="RollingIv"/>.</returns>
public RollingIv CreateDecryptIv(byte[] initialIv, VersionMaskType versionMaskType)
{
ushort versionMask = GetMaskedVersion(_version, versionMaskType);
return(new RollingIv(_decryptionAlgorithm, initialIv, versionMask));
}
